Neurohistology Flashcards
What is the origin of nervous tissue?
Ectodermally derived
What are the two principal cell types of nervous tissue?
Neurones and neuroglia
What are neurones specialised for?
Stimulus reception and conduction of impulse
What do dendrites do?
Receive information from adjacent axons
What do axons do?
Send information from one end of the neurone to the other
What happens at an axon hillock?
Summation of signals from the cell body
Which parts of the neurone are particularly rich in voltage-gated sodium channels?
Axon hillock, axon initial segment
What are microtubule associated proteins (MAP2)?
Cytoskeletal proteins found in dendrites
What is beta-IV spectrin?
Cytoskeletal protein found in axons
What do motor neurones do?
Relay information from the brain and spinal cord to muscles and glands
How does Golgi staining work?
Silver precipitation forms inside neurones when treated with potassium dichromate and silver nitrate
Where are the cell bodies of multipolar motor neurones found?
Ventral horn of the spinal cord
Where is Nissl substance largely absent?
Axon
What are spinal ganglia?
Aggregations of nerve cells outside the CNS
What do satellite cells do?
Surround individual ganglion cells
What are the three neuronal subtypes?
Motor, sensory, interneurone
What do interneurones do?
Integrate information from sensory to motor neurones
Which cortex is divided into six layers?
Cerebral cortex (neocortex)
What are the neocortex layers?
Molecular, external granular, external pyramidal, internal granular, internal pyramidal, multiform
What is white matter composed of?
Myelinated fibres
Which cortex is divided into three layers?
Cerebellar cortex
What are the layers of the cerebellar cortex?
Outer molecular, single layer of Purkinje cells, granular
What is in the outer molecular layer of the cerebellar cortex?
Basket and stellate cells
What is in the granular layer of the cerebellar cortex?
Granule and Golgi cells
What do Purkinje cells look like?
Pear-shaped bodies with distinctive dendritic tree
Which cells are the smallest and most abundant in the brain?
Granule cells
What is the blood-brain barrier composed of?
Endothelial cells joined by tight junctions
What is the purpose of the blood-brain barrier?
Prevents diffusion of solutes and fluid into the brain and spinal cord
What is the integrity of the blood-brain barrier dependent on?
Astrocyte end feet
Which neuroglia are found in the CNS?
Astrocytes, oligodendrocytes, microglia, ependymal cells
Which neuroglia are found in the PNS?
Schwann cells, satellite cells
Which neuroglia have myelinated axons?
Oligodendrocytes and Schwann cells
What do astrocytes do?
Provide structural and metabolic support for neurones
What do microglia do?
Immune function, much like macrophages of the CNS
What do oligodendrocytes do?
Form myelin sheath around multiple CNS axons
What do Schwann cells do?
Form myelin sheath around a single PNS axon
What is the purpose of myelination?
Provides insulation to enhance conduction velocity of action potentials
